Pet Doors for Basement Windows and Other Short Sideways Sliding Windows

Posted by Jon Mortensen on Jul 25th 2016

One question that we get quite often is: Do you have a pre-built cat door option for a short sideways sliding window like you would commonly find in a basement? The quick answer is no, but it is really easy to install a pet door in a window like this, and this blog will give you several options on how to get it done.

Pre-Built Options for Taller Sliding Windows

For horizontal sliding windows that are about 40" or taller, we will have some options. We can have a Thermo Panel 3e sliding glass pet door custom built shorter. This is more expensive than a regular sliding door pet door, and it takes about 5 weeks to build it, but they are available. For shorter windows there are no pre-built options, but making your own solution is pretty easy to do, and this blog will tell you how.

Choosing the Material for the Panel

First choice to make is the panel material, and there are two easy solutions. If this is in a basement or somewhere where it won't be seen, wood is going to be the cheapest option. When I did this for the video below, I used a 1" x 10" piece of pine wood, and it was wide enough for the small electronic pet door that I installed. Plywood works just as well. If it is going someplace where it will be visible, then a better option is to use Lexan (also called polycarbonate). This is a clear plastic like Plexiglas, but Plexiglas is brittle and hard to work with. Lexan or polycarbonate is much softer and easier to cut and drill holes into.


Most larger towns have a plastics store where you can purchase Lexan, and they will usually cut to whatever dimension you need, and would probably also cut the hole for the pet door to install into the Lexan as well. Here is a link to a local store in Seattle that I've purchased from called TAP Plastics, they do sell via mail order as well. If you're not handy, this might be the way to go. You can also find Lexan online, I recently purchased a piece that is 4' x 1' x 1/4" thick off of ebay for about $35. I would suggest using 1/4" thick Lexan for a pet door installation. You can go thicker than that, but it isn't necessary; Lexan is used for race car windows and bullet proof glass, so it's plenty tough.

Building the Panel


Once you have picked your panel material, it needs to be cut to the right height. If you measure the sliding window height and use that, it's a pretty safe bet. After all, the window fit into the track, so if your panel is built to that same height it should fit too; just put the top of your panel into the track and lift up and over the bottom wall. The wood or Lexan will not be as thick as your window is, so it will be loose in the track. You can screw it to the inside or outside of the track to keep it from moving. Another option is just to run some weather stripping tape down the track and down the side of the window, then squeeze the window into the pet door, and use the weatherstrip to hold the panel in place. Using a clamp on lock as shown in the video helps to keep the window tight against the cat door.

Cutting the Hole in the Panel


For this part of the job you need a drill and a jigsaw. Just trace the template onto the panel, drill a hole at the 4 corners, and connect the dots with the jigsaw. In the video below I describe building both of these panels in about 40 minutes, but what I neglected to show was the actual holes that I cut in the panels. I have the feeling that saying it's easy and then showing an end product that looks really good doesn't convince a person that isn't handy how easy this job is. The holes do not need to be perfect, by a long shot. The pet door will have a flange that covers over your cut hole, so you can have a really messy cut opening in the panel, and it won't show at all. This is what my workmanship looks like under the pet door frames. I only had a jigsaw blade for cutting curves when I decided to make the video. These thinner blades bend under pressure and it's more difficult to get a straight line out of them. You too can cut really bad looking holes and end up with a great looking result!

Choosing a Cat Door


Most of these installations are for cats in basement windows. Many pet doors are made to fit into a full thickness door that is 1 3/4" thick. These panels won't be thick enough for one of those doors, so we need to choose a door that works. The best choice for an electronic pet door is the SureFlap. It is activated by RFID chips. If your pet already has a chip implanted, it should work the SureFlap door. The other option is a collar key. The collar key is about the size of a nickel, and the collar is not included, just the key. For a non-electronic option, we like the Pride pet door because it works on any thickness surface.

Big Dog Door in a Short Window


In the video below, we have a pretty typical situation: the window is 15" tall. Because most medium pet door flaps are about 12 or 13 inches tall and have framing around them, they will not fit in a panel. The Pride pet door medium frame is 15 3/4" tall for example. If you have a medium dog and want to put it through a short window, we have one more trick up our sleeve. We can have a custom Hale pet door built to overlap the window frame just enough so that you can just open the window, install the pet door, and close the window right into the side of the dog door. This will maximize the size of the doggie door flap that you can fit within that limited space, and you can make the width to fit the pet, then just close the window right into the side of the doggy door.

Can't You Just Do It For Me?


Yes, we can. Give us a call and we will figure out the best pet door and material combination and build it to fit, cost will vary according to the size of the door and the material used. This is a custom order, so no returns or refunds will be allowed.